How frequently do hospital billing records indicate that patients experience harmful events suggesting potential gaps in patient safety?

Rates of six common potentially preventable adverse events and complications of care in the hospital (non-obstetric) ranged from 2.3 to 24.4 per 1,000 patients at risk in 2003. Rates for four of the six indicators were higher among the elderly. All six rates increased from 2000 to 2003.

Why is this important?

Patient safety means "avoiding injuries to patients from the care that is intended to help them" (IOM 2001). The Institute of Medicine's (IOM) landmark 1999 report, To Err Is Human, prompted national efforts to diminish threats to patient safety (IOM 1999). Before the IOM report, few tools and very little data were available to measure the scope and types of safety problems affecting patients.

As one response, the federal Agency for Healthcare Research and Quality created Patient Safety Indicators, which use hospital billing records to "screen for problems that patients experience as a result of exposure to the healthcare system, and that are likely amenable to prevention by changes at the system or provider level" (AHRQ 2003). For example:

• Pressure ulcers may often be prevented using best practices such as risk assessments, turning schedules, pressure reduction devices, incontinence management, and nutritional support (WOCN 2003; Reddy 2006). These practices are not often observed in hospitals, however (Lyder et al. 2001).
• Formation of blood clots in the leg (deep vein thrombosis), which may travel to and become lodged in the lungs (pulmonary embolism), can be prevented by following recommendations of the American College of Chest Physicians for use of anticoagulants, compression stockings, and pneumatic compression devices (Geerts et al. 2004).

Findings

During 2002, rates of six common potentially preventable, non-obstetric adverse events or complications of care that were recorded in hospital billing records varied in frequency (among patients at risk of developing them) and by patient age.

• Rates of three adverse events ranged from 2.3 hospital-acquired infections associated with use of intravenous lines and catheters per 1,000 patients, to 24.4 pressure ulcers per 1,000 patients hospitalized for five days or longer.
• Rates of three postoperative complications of care ranged from 4.6 cases of respiratory failure per 1,000 elective-surgery patients to 12.5 cases of sepsis per 1,000 elective-surgery patients hospitalized for three days or longer.
• Four of the six rates were highest in the elderly. For example, pressure ulcers were five times more prevalent in the elderly than among young adults, and rates of deep vein thrombosis or pulmonary embolism were more than two times higher in the elderly.

All six rates increased significantly from 2000 to 2003 (ranging from 12 percent higher for pressure ulcers to 35 percent higher for postoperative respiratory failure), and four of the six rates increased significantly from 2002 to 2003. Higher rates might indicate an increase in adverse events or that adverse events were more often recorded in hospital billing records (AHRQ 2006).

Implications

A study of 18 potentially preventable adverse events and complications of care (including those described above) found that they accounted for an estimated 2.4 million additional hospital days, 32,600 potentially preventable deaths, and $14.6 billion in additional cost to the health care system in 2000 (Zhan and Miller 2003). Some research finds that these costs are born by both payers and providers (Shannon et al. 2006; Zhan et al. 2006), suggesting that there is a financial as well as an ethical rationale for improving patient safety.

A review of research on adverse events in the elderly concluded that "[t]he main cause of these increased risks appears to be the diminished physiological reserve of elderly patients; however, age alone is a less important predictor of adverse events than comorbidities and functional status" (Rothschild et al. 2000). Therefore, experts recommend that hospitals perform a comprehensive geriatric assessment of elderly patients at hospital admission to predict risk of complications.

Improvement Ideas and Resources

A growing body of evidence supports the effectiveness of several patient safety practices (Shojania et al. 2001) and others have been endorsed by the National Quality Forum (NQF 2003). The Leapfrog Group, a coalition of large employers, annually surveys hospitals on their adherence to 30 of these safety practices.

Hospitals and coalitions can use patient safety indicators such as these to help identify potential problem areas for investigation and to develop strategies that promote patient safety through better organization, training, procedures, teamwork, and communication (Baker et al. 2005; Hickam et al. 2003). For example, some hospitals have increased adherence to recommended pressure ulcer prevention practices (Gibbons et al. 2006; Hiser et al. 2006; Lyder et al. 2004).

Nurse staffing has important implications for patient safety. Several studies have found that higher nurse staffing levels and skill-mix (e.g., proportion that are registered nurses or have a four-year college degree) are associated with lower rates of adverse events, life-threatening post-surgical complications, and deaths in the hospital, along with shorter hospital stays (Lankshear et al. 2005).

• Economic analyses suggest that increasing nurse staffing in hospitals might prevent from 1,800 to 72,000 patient deaths at an estimated net cost ranging from $4.2 billion to $7.3 billion annually, depending on assumptions (Needleman et al. 2006; Rothberg et al. 2005).
• Increasing the proportion of registered nurses might prevent up to 5,000 hospital deaths and yield net cost-savings of $242 million annually (Needleman et al. 2006).

Measure:

Rates were calculated using the Agency for Healthcare Research and Quality's Patient Safety Indicators, which were refined through a review of validity, reliability, and usefulness by researchers at the University of California, San Francisco, and Stanford University (AHRQ 2003). The denominators are limited to patients of short-stay, community hospitals most likely to be at risk for the event or complication. The numerators are based on secondary diagnoses only, to exclude complications that were present on admission. Rates were adjusted by age, gender, age-gender interactions, comorbidities, and diagnosis-related group (DRG) clusters.

• Decubitus ulcer per 1,000 discharges of length five or more days, excluding paralysis patients, patients admitted from long-term care facilities, neonates, obstetrical admissions, and patients with diseases of the skin, subcutaneous tissue, and breast.
• Accidental puncture or laceration during procedures per 1,000 discharges, excluding obstetric admissions. Also excludes admissions specifically for such problems, such as cases from earlier admissions or from other hospitals.
• Infections due to medical care (primarily related to intravenous lines and catheters) per 1,000 discharges, excluding immunocompromised patients, cancer patients, and neonates. Also excludes admissions specifically for such infections, such as cases from earlier admissions, from other hospitals, or from other settings.
• Postoperative sepsis per 1,000 elective-surgery discharges of longer than three days, excluding patients admitted for infection, patients with cancer or immunocompromised states, and obstetric conditions.
• Postoperative pulmonary embolism or deep vein thrombosis per 1,000 surgical discharges, excluding patients admitted for deep vein thrombosis, obstetrics, and secondary procedure of plication of vena cava before or after surgery. Also excludes admissions specifically for such thromboembuli, such as cases from earlier admissions, from other hospitals, or from other settings.
• Postoperative respiratory failure per 1,000 elective-surgery discharges, excluding patients with respiratory disease, circulatory disease, and obstetric conditions (a new code for acute and respiratory failure was introduced in 1998).

Limitations:

These findings are not definitive because of the limitations of the administrative data on which they are based. Changes in some rates could be caused, in part, by changes in coding practices or improved detection of adverse events over time. These rates do not capture hospital readmissions for problems such as deep vein thrombosis that occur after hospital discharge but might be preventable with better patient education (Weller et al. 2004).

Source:

Rates were calculated by the Agency for Healthcare Research and Quality (AHRQ 2006) using data from the Healthcare Cost and Utilization Project, National Inpatient Sample, approximating a 20 percent stratified sample of discharges from U.S. short-stay community hospitals.

References:

* Indicates source of data used in the chart(s).AHRQ (Agency for Healthcare Research and Quality). 2003. AHRQ Quality Indicators: Guide to Patient Safety Indicators. AHRQ Pub. 03-R203, revision 1. Rockville, Md.: U.S. Department of Health and Human Services.

* AHRQ (Agency for Healthcare Research and Quality). 2006. HCUPnet: Healthcare Cost and Utilization Project. Rockville, Md.: U.S. Department of Health and Human Services.

Baker, D. P., S. Gustafson, J. Beaubien et al. 2005. Medical Teamwork and Patient Safety: The Evidence-Based Relation. AHRQ Publication No. 05-0053. Rockville, Md.: Agency for Healthcare Research and Quality.

Geerts, W. H., G. F. Pineo, J. A. Heit et al. 2004. Prevention of Venous Thromboembolism: The Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy. Chest 126 (3 Suppl): 338S–400S.

Gibbons, W., H. T. Shanks, P. Kleinhelter et al. 2006. Eliminating Facility-Acquired Pressure Ulcers at Ascension Health Joint Commission Journal on Quality and Patient Safety 32 (9): 488–96.

Hickam, D. H., S. Severance, A. Feldstein et al. 2003. The Effect of Health Care Working Conditions on Patient Safety. Vol. 74 of Evidence Report/Technolology Assessment AHRQ Publication No. 03-E031. Rockville, Md.: Agency for Healthcare Research and Quality.

Hiser, B., J. Rochette, S. Philbin et al. 2006. Implementing a Pressure Ulcer Prevention Program and Enhancing the Role of the CWOCN: Impact on Outcomes. Ostomy/Wound Management 52 (2): 48–59.

IOM (Institute of Medicine). 1999. To Err Is Human: Building a Safer Health Care System. Washington, D.C.: National Academy Press.

IOM (Institute of Medicine). 2001. Crossing the Quality Chasm: A New Health System for the 21st Century. Washington, D.C.: National Academy Press.

Lankshear, A. J., T. A. Sheldon, and A. Maynard. 2005. Nurse Staffing and Healthcare Outcomes: A Systematic Review of the International Research Evidence. Advances in Nursing Science 28 (2): 163–74.

Lyder, C. H., J. Grady, D. Mathur et al. 2004. Preventing Pressure Ulcers in Connecticut Hospitals by Using the Plan-Do-Study-Act Model of Quality Improvement. Joint Commission Journal on Quality and Patient Safety 30 (4): 205–14.

Lyder, C. H., J. Preston, J. N. Grady et al. 2001. Quality of Care for Hospitalized Medicare Patients at Risk for Pressure Ulcers. Archives of Internal Medicine 161 (12): 1549–54.

Needleman, J., P. I. Buerhaus, M. Stewart et al. 2006. Nurse Staffing in Hospitals: Is There a Business Case for Quality? Health Affairs (Millwood) 25 (1): 204–11.

NQF (National Quality Forum). 2003. Safe Practices for Better Healthcare: A Consensus Report. Washington, D.C.: National Quality Forum.

Reddy, M., S. S. Gill, and P. A. Rochon. 2006. Preventing Pressure Ulcers: A Systematic Review. Journal of the American Medical Association 296 (8): 974–84.

Rothberg, M. B., I. Abraham, P. K. Lindenauer et al. 2005. Improving Nurse-to-Patient Staffing Ratios as a Cost-Effective Safety Intervention. Medical Care 43 (8): 785–91.

Rothschild, J. M., D. W. Bates, and L. L. Leape. 2000. Preventable Medical Injuries in Older Patients. Archives of Internal Medicine 160 (18): 2717–28.

Shannon, R. P., B. Patel, D. Cummins et al. 2006. Economics of Central Line-Associated Bloodstream Infections. American Journal of Medical Quality 21 (6 Suppl): 7S–16S.

Shojania, K. G., B. W. Duncan, K. M. McDonald et al. 2001. Making Health Care Safer: A Critical Analysis of Patient Safety Practices. Evidence Report/Technology Assessment (Summary) (43): i–x, 1–668.

Weller, W. E., B. K. Gallagher, L. Cen et al. 2004. Readmissions for Venous Thromboembolism: Expanding the Definition of Patient Safety Indicators. Joint Commission Journal on Quality and Patient Safety 30 (9): 497–504.

WOCN (Wound Ostomy and Continence Nurses Society). 2003. Guidelines for Prevention and Management of Pressure Ulcers. Glenview, Ill.: WOCN Society.

Zhan, C., and M. R. Miller. 2003. Excess Length of Stay, Charges, and Mortality Attributable to Medical Injuries During Fospitalization. Journal of the American Medical Assocation 290 (14): 1868–74.